A-1（ダッシュボード画面）の実装が完了しました。

実装内容:

バックエンド: summary APIに total_fields, assigned_fields, unassigned_fields を追加
フロントエンド: /dashboard に新画面を作成
概要サマリー: 全圃場数 / 作付け済み / 未割当（警告アイコン付き）
作物別集計テーブル（筆数・面積・合計行）
クイックアクセス: 4つのボタン（作付け計画・圃場管理・帳票出力・データ取込）
年度セレクタで切替可能
Navbar: 「ホーム」ボタン追加、KeinaSystemロゴクリックでダッシュボードへ
ルート (/): /allocation → /dashboard にリダイレクト先変更
http://localhost:3000/dashboard で確認できます。

残りタスク: A-7（検索・フィルタ）のみです

frontend/src/app/dashboard/page.tsx

@@ -0,0 +1,166 @@
+'use client';
+
+import { useState, useEffect } from 'react';
+import { useRouter } from 'next/navigation';
+import { api } from '@/lib/api';
+import Navbar from '@/components/Navbar';
+import { Wheat, MapPin, FileText, Upload, Loader2, AlertTriangle } from 'lucide-react';
+
+interface SummaryData {
+  year: number;
+  total_fields: number;
+  assigned_fields: number;
+  unassigned_fields: number;
+  total_plans: number;
+  total_area: number;
+  by_crop: { crop: string; count: number; area: number }[];
+}
+
+export default function DashboardPage() {
+  const router = useRouter();
+  const currentYear = new Date().getFullYear();
+  const [year, setYear] = useState(currentYear);
+  const [summary, setSummary] = useState<SummaryData | null>(null);
+  const [loading, setLoading] = useState(true);
+
+  useEffect(() => {
+    const fetchSummary = async () => {
+      setLoading(true);
+      try {
+        const res = await api.get(`/plans/summary/?year=${year}`);
+        setSummary(res.data);
+      } catch (error) {
+        console.error('Failed to fetch summary:', error);
+      } finally {
+        setLoading(false);
+      }
+    };
+    fetchSummary();
+  }, [year]);
+
+  const years = [];
+  for (let y = currentYear + 1; y >= currentYear - 3; y--) {
+    years.push(y);
+  }
+
+  return (
+    <div className="min-h-screen bg-gray-50">
+      <Navbar />
+      <div className="max-w-4xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
+        {/* ヘッダー */}
+        <div className="flex items-center justify-between mb-6">
+          <h1 className="text-2xl font-bold text-gray-900">ダッシュボード</h1>
+          <select
+            value={year}
+            onChange={(e) => setYear(Number(e.target.value))}
+            className="px-3 py-2 border border-gray-300 rounded-md text-sm"
+          >
+            {years.map((y) => (
+              <option key={y} value={y}>{y}年度</option>
+            ))}
+          </select>
+        </div>
+
+        {loading ? (
+          <div className="flex items-center justify-center py-16">
+            <Loader2 className="h-8 w-8 animate-spin text-gray-400" />
+          </div>
+        ) : summary ? (
+          <div className="space-y-6">
+            {/* 概要サマリーカード */}
+            <div className="grid grid-cols-1 sm:grid-cols-3 gap-4">
+              <div className="bg-white rounded-lg shadow p-5">
+                <p className="text-sm text-gray-500">全圃場数</p>
+                <p className="text-3xl font-bold text-gray-900 mt-1">{summary.total_fields}<span className="text-base font-normal text-gray-500 ml-1">筆</span></p>
+              </div>
+              <div className="bg-white rounded-lg shadow p-5">
+                <p className="text-sm text-gray-500">作付け済み</p>
+                <p className="text-3xl font-bold text-green-600 mt-1">{summary.assigned_fields}<span className="text-base font-normal text-gray-500 ml-1">筆</span></p>
+              </div>
+              <div className="bg-white rounded-lg shadow p-5">
+                <p className="text-sm text-gray-500">未割当</p>
+                <div className="flex items-center mt-1">
+                  <p className={`text-3xl font-bold ${summary.unassigned_fields > 0 ? 'text-amber-500' : 'text-gray-400'}`}>
+                    {summary.unassigned_fields}<span className="text-base font-normal text-gray-500 ml-1">筆</span>
+                  </p>
+                  {summary.unassigned_fields > 0 && (
+                    <AlertTriangle className="h-5 w-5 text-amber-500 ml-2" />
+                  )}
+                </div>
+              </div>
+            </div>
+
+            {/* 作物別集計 */}
+            {summary.by_crop.length > 0 && (
+              <div className="bg-white rounded-lg shadow p-5">
+                <h2 className="text-lg font-semibold text-gray-900 mb-3">作物別集計</h2>
+                <table className="w-full text-sm">
+                  <thead>
+                    <tr className="border-b border-gray-200">
+                      <th className="text-left py-2 text-gray-500 font-medium">作物</th>
+                      <th className="text-right py-2 text-gray-500 font-medium">筆数</th>
+                      <th className="text-right py-2 text-gray-500 font-medium">面積（反）</th>
+                    </tr>
+                  </thead>
+                  <tbody>
+                    {summary.by_crop.map((item) => (
+                      <tr key={item.crop} className="border-b border-gray-100">
+                        <td className="py-2 text-gray-900">{item.crop}</td>
+                        <td className="py-2 text-right text-gray-700">{item.count}</td>
+                        <td className="py-2 text-right text-gray-700">{item.area.toFixed(1)}</td>
+                      </tr>
+                    ))}
+                    <tr className="font-semibold">
+                      <td className="py-2 text-gray-900">合計</td>
+                      <td className="py-2 text-right text-gray-900">{summary.total_plans}</td>
+                      <td className="py-2 text-right text-gray-900">{summary.total_area.toFixed(1)}</td>
+                    </tr>
+                  </tbody>
+                </table>
+              </div>
+            )}
+
+            {/* クイックアクセス */}
+            <div className="bg-white rounded-lg shadow p-5">
+              <h2 className="text-lg font-semibold text-gray-900 mb-3">クイックアクセス</h2>
+              <div className="grid grid-cols-2 sm:grid-cols-4 gap-3">
+                <button
+                  onClick={() => router.push('/allocation')}
+                  className="flex flex-col items-center p-4 rounded-lg border border-gray-200 hover:bg-green-50 hover:border-green-300 transition-colors"
+                >
+                  <Wheat className="h-6 w-6 text-green-600 mb-2" />
+                  <span className="text-sm text-gray-700">作付け計画</span>
+                </button>
+                <button
+                  onClick={() => router.push('/fields')}
+                  className="flex flex-col items-center p-4 rounded-lg border border-gray-200 hover:bg-blue-50 hover:border-blue-300 transition-colors"
+                >
+                  <MapPin className="h-6 w-6 text-blue-600 mb-2" />
+                  <span className="text-sm text-gray-700">圃場管理</span>
+                </button>
+                <button
+                  onClick={() => router.push('/reports')}
+                  className="flex flex-col items-center p-4 rounded-lg border border-gray-200 hover:bg-purple-50 hover:border-purple-300 transition-colors"
+                >
+                  <FileText className="h-6 w-6 text-purple-600 mb-2" />
+                  <span className="text-sm text-gray-700">帳票出力</span>
+                </button>
+                <button
+                  onClick={() => router.push('/import')}
+                  className="flex flex-col items-center p-4 rounded-lg border border-gray-200 hover:bg-orange-50 hover:border-orange-300 transition-colors"
+                >
+                  <Upload className="h-6 w-6 text-orange-600 mb-2" />
+                  <span className="text-sm text-gray-700">データ取込</span>
+                </button>
+              </div>
+            </div>
+          </div>
+        ) : (
+          <div className="text-center py-16 text-gray-500">
+            データの取得に失敗しました
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

frontend/src/app/fields/page.tsx

@@ -34,7 +34,7 @@ export default function FieldsPage() {
     try {
       const response = await api.get(`/fields/?ordering=${sortOrder}`);
       setFields(response.data);
-      const groups = [...new Set(response.data.map((f: Field) => f.group_name).filter(Boolean))] as string[];
+      const groups = Array.from(new Set<string>(response.data.map((f: Field) => f.group_name).filter(Boolean)));
       setUniqueGroups(groups.sort());
     } catch (error) {
       console.error('Failed to fetch fields:', error);

frontend/src/app/page.tsx

@@ -9,7 +9,7 @@ export default function Home() {
   useEffect(() => {
     const token = localStorage.getItem('accessToken');
     if (token) {
-      router.push('/allocation');
+      router.push('/dashboard');
     } else {
       router.push('/login');
     }

frontend/src/components/Navbar.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import { useRouter, usePathname } from 'next/navigation';
-import { LogOut, Wheat, MapPin, FileText, Upload } from 'lucide-react';
+import { LogOut, Wheat, MapPin, FileText, Upload, LayoutDashboard } from 'lucide-react';
 import { logout } from '@/lib/api';
 
 export default function Navbar() {
@@ -19,8 +19,21 @@ export default function Navbar() {
       <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
         <div className="flex justify-between h-16">
           <div className="flex items-center space-x-8">
-            <h1 className="text-xl font-bold text-green-700">KeinaSystem</h1>
+            <button onClick={() => router.push('/dashboard')} className="text-xl font-bold text-green-700 hover:text-green-800 transition-colors">
+              KeinaSystem
+            </button>
             <div className="flex items-center space-x-4">
+              <button
+                onClick={() => router.push('/dashboard')}
+                className={`flex items-center px-3 py-2 text-sm rounded-md transition-colors ${
+                  isActive('/dashboard')
+                    ? 'text-green-700 bg-green-50'
+                    : 'text-gray-700 hover:text-gray-900 hover:bg-gray-100'
+                }`}
+              >
+                <LayoutDashboard className="h-4 w-4 mr-2" />
+                ホーム
+              </button>
               <button
                 onClick={() => router.push('/allocation')}
                 className={`flex items-center px-3 py-2 text-sm rounded-md transition-colors ${

frontend/tsconfig.json

@@ -22,5 +22,5 @@
     }
   },
   "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
-  "exclude": ["node_modules"]
+  "exclude": ["node_modules", "playwright.config.ts", "e2e"]
 }